electrical engineering MCQs – Page 12

Practise multiple-choice questions from electrical engineering for competitive examinations and subject revision. Review each marked answer and report any item that may be outdated or unclear.

electrical engineering Mcqs

1. economics of power generation 2. analog electronics 3. solid state switching circuits 4. parallel circuits 5. switchgear and protection 6. op amp circuits 7. transistor audio power amplifiers 8. electrostatics 9. heating and welding 10. multi stage transistor amplifiers 11. passive filters 12. network theorems 13. regulated d c power supply 14. a c fundamentals circuits and circuit theory 15. electromagnetic induction 16. power electronics 17. magnetism and electromagnetism 18. transformers 19. modulation and demodulation 20. d c generators 21. semiconductor theory 22. single phase induction motors 23. semiconductor diode 24. hybrid parameters 25. digital electronics 26. oscillators 27. earthing or grounding 28. single stage transistor amplifiers 29. d c motors 30. transistor biasing 31. amplifiers with negative feedback 32. basic electrical 33. electronic instruments 34. synchronous motors 35. field effect transistors fet 36. magnetic circuit 37. control systems 38. industrial drives 39. power generation 40. series parallel circuits 41. transistor tuned amplifiers 42. electrical engineering materials 43. rectifiers and converters 44. integrated circuits 45. scr silicon controlled rectifiers 46. cables 47. polyphase induction motors 48. measurement and instrumentation 49. transistors 50. electrical machine design 51. electrolysis and storage of batteries 52. electric traction 53. transmission and distribution

221. One newton meter is same as_____________?
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A. one joule

B. one joule second

C. one watt

D. five joules

222. A resistance having rating 10 ohms, 10 W is likely to be a__________?
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A. variable resistor

B. carbon resistor

C. metallic resistor

D. wire wound resistor

223. A MOSFET, for its conduction uses_____________?
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A. Only minority carriers

B. Only majority carriers

C. Both minority and majority carriers

D. None of these

224. The no-load current drawn by transformer is usually what per cent of the full-load current ?
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A. 20 to 30 per cent

B. 12 to 15 per cent

C. 0.2 to 0.5 per cent

D. 2 to 5 per cent

225. The resistance of a copper wire 200 m long is 21 Q. If its thickness (diameter) is 0.44 mm, its specific resistance is around_______________?
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A. 1.8 x 10?8 Q-m

B. 1.6 x 10?8 Q-m

C. 1.4 x 10~8 Q-m

D. 1.2 x 10~8 Q-m

226. Silicon controlled rectifier can be turned on____________?
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A. By making current non zero and turned off by making current zero

B. And turned off by applying gate pulse

C. By applying a gate pulse and turned off by removing the gate pulse

D. By applying a gate pulse and turned off only when current becomes zero

227. Which of the following loss in a transformer is zero even at full load ____________?
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A. Friction loss

B. Core loss

C. Hysteresis loss

D. Eddy current loss

228. In the SPWM, the modulating signal is___________?
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A. Triangular

B. Square

C. Saw tooth

D. Sinusoidal

229. Current velocity through a copper conductor is___________?
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A. of the order of a few ^.s/m

B. nearly 3 x 108 m/s

C. the same as propagation velocity of electric energy

D. independent of current strength

230. The chemical used in breather is_______________?
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A. asbestos fiber

B. sodium chloride

C. silica sand

D. silica gel

231. When secondary of a current transformer is open-circuited its iron core will be__________?
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A. hot because of heavy iron losses taking place in it due to high flux density

B. cool as there is no secondary current

C. none of above will happen

D. hot because primary will carry heavy current

232. Which of the following is the main advantage of an auto-transformer over a two winding transformer?
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A. Eddy losses are totally eliminated

B. Hysteresis losses are reduced

C. Saving in winding material

D. Copper losses are negligible

233. Silicon steel used in laminations mainly reduces___________?
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A. eddy current losses

B. hysteresis loss

C. copper losses

D. all of the above

234. If the percentage impedances of the two transformers working in parallel are different, then______________________?
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A. transformers will be overheated

B. power factors of both the transformers will be same

C. parallel operation will be not possible

D. parallel operation will still be possible, but the power factors at which the two transformers operate will be different from the power factor of the common load

235. In a push pull converter, the filter capacitor can be obtained as____________?
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A. Cmin= ( 1 D ) V / ( Vr L f2 )

B. Cmin= ( 1 2 D ) V / 32 ( Vr L f2 )

C. Cmin= ( 1 2 D ) V / 42 ( Vr L f2 )

D. Cmin = V / ( Vr L f2 )

236. When resistance element of a heater fuses and then we reconnect it after removing a portion of it, the power of the heater will___________?
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A. none of the above

B. remain constant

C. decrease

D. increase

237. In the case of direct current____________?
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A. magnitude and direction of current remains constant